Biological Apporach To Explaining OCD Flashcards
Describe Lewis’s research into genetic explanations of OCD
Of his OCD patients 37% had parents with OCD and 21% had siblings with OCD. Suggests OCD runs in families.
What does the diathesis stress model suggest about genetic explanations of OCD
Certain genes are more likely to cause mental health problems and environment can trigger it.
Describe how candidate genes explain OCD
Identified certain genes which creates OCD
5HTI-D beta is implicated in the efficiency of transport of serotonin.
What is meant by OCD being polygenic?
OCD caused by several genes
Taylor: analysed findings of previous studies —> 250 genes involved in OCD
Genes associated with dopamine and serotonin (mood regulation)
Different genes can cause OCD in different people. Explain this.
One gene group could cause OCD in one person and another gene group could cause OCD in someone else. (Aetiologically heterogeneous)
Different types of OCD could be the result of hoarding or religion etc…..
Describe the supporting evidence for genetic explanations (AO3)
Some people are more vulnerable to OCD as a result of genetic makeup.
Nestadt et al: twin studies, 68% of identical twins shared OCD opposed to 31% non identical.
Strongly suggests genetic influence on OCD
Describe one limitation of genetic explanations of OCD (AO3)
Although twin studies suggest OCD largely genetic. Psychologists have been unsuccessful in identifying genes involved in OCD.
Appears many genes involved and genetic variation only increases OCD risk by a fraction. Genetic variation not useful as little practical value.
Describe serotonins role in OCD (neural explanation)
Low levels of serotonin then normal transmission of mood related information does not take place and mental processing is effected (OCD linked to reduced Serotonin)
Explain how decision making links to OCD
May be associated with abnormal function of frontal lobes (logical thinking)
Left parahippocampal gyrus associated with unpleasant emotions and OCD.
Describe the support for neural explanations (AO3)
Eg. Antidepressants work purely on serotonin system, increasing the levels. These are effective in lowering OCD symptoms suggesting serotonin is involved in OCD.
OCD symptoms form parts of other conditions eg. Parkinson’s. Suggests biological processes cause symptoms of those diseased may be responsible for OCD.
Explain why it is not clear what neural mechanisms are involved in OCD (AO3)
Studies on decision making are same neural systems that function abnormally in OCD.
However, research has also identifies other brain systems that may be involved sometimes. (No system found that is always plays a role in OCD)
Cannot claim to understand neural mechanisms in OCD.
